1. Field of the Invention
The present invention relates to compact line printers of the type having integral print media feeding and more particularly to constructions for enabling such printers to selectively handle either cut-sheet or continuous print media.
2. Background Art
With the increasing popularity of "personal" computers and word processors, there has developed a need for similarly "personal" printers of their output. To the extent that the computers and word processors become smaller in size and more portable, there is a commensurate desire that the output printers have the same characteristics. Various small size, dot matrix printers, which are capable of printing on cut-sheet, fanfold and tractor-feed media formats, are available. However, these printers generally require hand-insertion of each successive cut-sheet print medium.
Automatic sheet feeding accessories are available for use with such compact printers, but these devices are separate units from the printer and present several disadvantages. For example, these separate sheet feeders create bulk to the overall system, as well as making it aesthetically unpleasing. The separate feeder approach involves a separate motor, drive transmission and feed elements, causing it to be a costly system addition. Moreover, there must be separate umbilical lines coupling the printer and feeder, and "cords" are always a target for elimination.
From another viewpoint, the add-on sheet feeder approach requires troublesome operator activities when setting up the printing system and when changing between different types of print media, e.g. from discrete sheet to fanfold media. The add-on approach causes complexities in the sheet feed path, which can render the system subject to jams and misfeeds. Also from the functional viewpoint, the add-on approach requires an escape code from the host computer to initiate a sheet feed sequence. The use of this extra code is very inconvenient when utilizing some software packages, e.g. for word processing applications, that do not support such an extra code.
Concurrently filed U.S. application Ser. No. 20,416, entitled "Compact Printer Having An Integral Cut-Sheet Feeder" discloses a printer/feeder which eliminates or significantly reduces such disadvantages of the prior art devices. In general, that printer/feeder provides a transport member which serves to selectively feed face sheets from a supply stack housed within the printer, as well as to transport feed sheets sequentially along a print path including an ingress, print zone and egress. In a preferred embodiment, the transport member comprises a cylindrical platen especially sized and configured to cooperate with sheets and feed paths of predetermined dimension.
It is desirable for a compact printer such as described in the above-noted application to have the capability for handling continuous print media, e.g. tractor-fed media, in the event the operation or printing application favors this mode. However, sheet and continuous print media present different input/output handling requirements.